This question was posted by another person in another forum which I'm equally keen to know the answer but unfortunately there isn't any reply. Here goes:
Most of us Time Machine users know that if you leave iphoto open, Time Machine won't back it up until you close it. Another annoying bug I've found is that even once you close it, Time Machine won't back up the latest set of photos you have imported. To make that happen, I have to import a new dummy photo so I have at least one new import, delete it, then close down iphoto and force a Time Machine backup.
This behaviour has been reported by others, you can try it for your self by importing some new photos, closing down iphoto, then going to where your Time Machine archive is stored, finding the iphoto package, open by right clicking and showing package contents, and looking to see if a folder of your imports has been created in the Originals directory.
You can also see this behaviour by monitoring Time Machine on its first backup after you import photos and close down iphoto. Just click on the Time Machine icon at the top of your screen while it is rotating, it will tell you how many items it is backing up and the size. If you have imported a large set of photos you'll notice that it obviously isn't being backed up.
So, to summarize, I always close iphoto after importing my latest new photos. I open it again and import a single photo, which I immediately delete, close iphoto, and manually force a Time Machine backup.
Most of us Time Machine users know that if you leave iphoto open, Time Machine won't back it up until you close it. Another annoying bug I've found is that even once you close it, Time Machine won't back up the latest set of photos you have imported. To make that happen, I have to import a new dummy photo so I have at least one new import, delete it, then close down iphoto and force a Time Machine backup.
This behaviour has been reported by others, you can try it for your self by importing some new photos, closing down iphoto, then going to where your Time Machine archive is stored, finding the iphoto package, open by right clicking and showing package contents, and looking to see if a folder of your imports has been created in the Originals directory.
You can also see this behaviour by monitoring Time Machine on its first backup after you import photos and close down iphoto. Just click on the Time Machine icon at the top of your screen while it is rotating, it will tell you how many items it is backing up and the size. If you have imported a large set of photos you'll notice that it obviously isn't being backed up.
So, to summarize, I always close iphoto after importing my latest new photos. I open it again and import a single photo, which I immediately delete, close iphoto, and manually force a Time Machine backup.